Two suppliers quote for the same modular cleanroom. Both list wall panels, a ceiling, HEPA filtration, doors, and lighting. The totals are far apart. Before asking either supplier for a discount, check whether they have priced the same job.
One proposal may cover a delivered kit. The other may include site assembly, electrical connections, air-system adjustment, and testing. Neither scope is automatically wrong, but they cannot be compared as if they end at the same point.
A useful modular cleanroom quotation tells you what will be supplied, what the finished installation is expected to do, and what you must arrange separately. Here is how to read it before committing to the project.
Start with the drawing, not the price per square metre
A room described as “100 square metres” leaves plenty of room for different assumptions. Is that the outside footprint or usable production space? Does it include the changing area? What is the internal clear height? Are the material-transfer area and corridor inside that figure?
A compact electronics assembly area, for example, may need benches, incoming-tray storage, an inspection station, and space to move completed parts to packaging. If the quotation uses every square metre for production benches, the missing access and support space will appear as a problem later.
Give each supplier the same marked drawing, with a date or revision number. Show equipment dimensions, door openings, personnel entry, material movement, and any space that must remain accessible for maintenance. Ask the supplier to identify assumptions rather than quietly filling in the gaps.
The modular cleanroom layout is also where STJH can help review the scope. A workable quotation follows the process through the room: where material enters, where it is exposed, where operators work, and how finished products leave.
“ISO Class 7” does not describe the whole specification
Cleanliness is an important target, but a class number is not a complete list of equipment or environmental requirements. ISO 14644-1 addresses air cleanliness classification by airborne particle concentration. It does not, by itself, specify your room temperature, humidity range, process exhaust, or all the conditions needed by your product.
If the project requires ISO Class 7, the quotation should identify the area covered and the occupancy state to be tested. A proposal based on an empty room is not directly comparable with one required to demonstrate performance while the agreed equipment and personnel are operating.
Temperature and humidity deserve their own lines. Ask what range is included, what operating conditions the design assumes, and whether the supplier has allowed for equipment heat, personnel, outside air, and exhaust. Supplying FFUs does not mean that cooling or humidity control has been included.
Do the same for pressure relationships. If a process extracts air from the room, who has allowed for replacement air? Which contractor connects and adjusts the exhaust? These questions need answers before the equipment list is treated as final.
Make the boundary between supplier and factory visible
The most useful sentence in a quotation can be the one that says exactly where the supplier's work stops. “Electrical included” is vague. “Internal wiring from the cleanroom distribution panel to the listed FFUs and lights; incoming power by the customer” is something the project team can plan around.
The same applies to flooring, ductwork, and installation. An existing floor may need preparation before it can receive the specified finish. A wall system may arrive ready to assemble but still require lifting equipment and trained installers. An air-handling unit may be supplied without the route that connects it to the room.
Use a comparison sheet like the one below. Mark each item as included, optional, by customer, or unresolved. An empty cell should be a question, not an assumed inclusion.
| Quotation item | Detail to ask for | Why it changes the comparison |
|---|---|---|
| Walls, ceiling, doors, and windows | Layout revision, dimensions, material specification, quantities, and installation details | Similar-looking rooms can have different usable space, construction, and cleaning requirements |
| FFUs and filters | Equipment schedule, filter specification, controls, and access for replacement | A total number of units alone does not explain the proposed system |
| Air conditioning and humidity control | Design conditions, assumed loads, equipment, ductwork, and connections | The room may depend on services that are absent from the supply price |
| Floor and site preparation | Required starting condition, preparation work, finish, and responsible contractor | An unfinished or unsuitable site creates work before assembly can begin |
| Installation | Assembly labour, supervision, lifting equipment, travel, and utility connection responsibilities | Installation guidance and a complete site installation are different scopes |
| Commissioning and testing | Adjustments, test list, operating conditions, acceptance criteria, and report provider | Completion of construction is not the same milestone as accepted performance |
| Transport and delivery | Packing, delivery destination, unloading arrangements, and stated exclusions | A factory supply price may exclude costs needed to get the system into your workshop |
For an overseas project, identify who is doing the local work. If the offer provides drawings and remote installation guidance, have the local contractor review them before the order is placed. Where site supervision is proposed, agree on its duration and the work that must be ready when the supervisor arrives.
Ask what “finished” means
A room can look complete while the air system still needs balancing or the controls need adjustment. If the production schedule assumes that manufacturing starts the morning after the final panel is fitted, it may be missing commissioning time.
Ask for separate milestones for supply, installation, cleaning, commissioning, and agreed performance tests. They may be close together, but they are not interchangeable.
ISO 14644-4 covers the process from cleanroom requirements through design, construction, and start-up. In a purchase proposal, those stages should translate into named tasks and responsibilities rather than a broad promise that the room is “ISO compliant.”
The test scope needs enough detail to price. Depending on the project, it may include particle classification, airflow checks, filter-installation checks, pressure measurements, or temperature and humidity records. Identify the applicable methods and agreed limits; do not assume that every possible test is included.
Also ask what happens if an agreed result is not achieved. Who investigates, who makes adjustments, and how is retesting handled? Clarify the handover documents: the final layout, equipment information, test reports, operating instructions, and maintenance requirements.
STJH can discuss these deliverables as part of the proposed cleanroom scope. They should be settled while the quotation is being reviewed, when changes can still be priced and scheduled clearly.
Reduce cost by changing the brief carefully
Once both quotations cover the same requirements, a price difference is easier to investigate. It may reflect different equipment, installation arrangements, materials, or design choices. Ask for the reason behind the difference and the effect of any proposed substitution.
If the budget is too high, first look at what genuinely needs environmental control. A local clean booth may be worth assessing where only one exposed process needs protection. It is not a direct replacement for an enclosed room with controlled entry, pressure relationships, or demanding temperature and humidity requirements.
Existing services can sometimes be used, but “the factory already has air conditioning” is not enough information to remove cooling equipment from a quotation. The available capacity, operating conditions, and connection arrangement need to be checked.
Likewise, reducing the number of filters or choosing a different panel should not be an isolated price negotiation. Ask the designer to explain how the revised system still meets the agreed requirements. If the required performance changes, make that change explicit in the proposal.
Keep operating costs in view as well. For a room that will run for long shifts, request the proposed operating schedule, equipment power information, filter-access arrangements, and maintenance needs. An operating-cost estimate is only useful if the assumptions are stated. A room using the host factory's cooling still creates a load on that system.
Send one project brief and get a quotation you can use
Before requesting a revised price, collect the unanswered questions in one place. A short project brief can cover the product and process, layout, cleanliness target, working hours, equipment heat and exhaust, personnel numbers, available services, and intended start date. Include photographs if the room will be built inside an existing workshop.
Ask each supplier to return the marked layout, equipment schedule, scope of supply, exclusions, site requirements, delivery basis, and acceptance plan. Have them identify which items are firm and which remain provisional because site information is missing.
This gives the purchasing team something better than two headline totals. It shows the cost of the specified room, the work still to be arranged locally, and the decisions that could change the budget. It also gives the installation team a clearer starting point once the order is approved.
For the site-planning side of the job, see our guide to installing a modular cleanroom in an existing factory.
If you are preparing a modular cleanroom quotation request, send STJH your layout and process requirements through the project inquiry form or email [email protected]. Tell us which work you want included and which services your factory already has. We can then discuss a scope that fits the project, with the assumptions and remaining questions visible from the beginning.